Hydraulic jet propulsion apparatus for water-borne craft



July 16, 1963 c. w.- F. HAMILTON 3,097,623

HYDRAULIC JET PROPULSION APPARATUS FORWATER-BORNE CRAFT 2 Sheets-Sheet 1 Filed April 26, 1951 FIG-.1

PIC-3.4

FIG. 3

July 16, 1963 c. w. F. HAMILTON 3,097,623

HYDRAULIC JET PROPULSION APPARATUS FOR WATER-BORNE CRAFT Filed April 26, 1961 2 Sheets-Sheet 2 I FIG. 2

FIG.5

United States Patent 3,097,623 HYDRAULIC JET PROPULSION APPARATUS FOR WATER-BORNE CRAFT Charles W. F. Hamilton, Irishman Creek, Private Bag, Timaru, Canterbury, New Zealand Filed Apr. 26, 1961, Ser. No. 105,816 Claims priority, application New Zealand Apr. 30, 1960 7 Claims. (Cl. 115-12) The invention relates to hydraulic jet propulsion apparatus for water-borne craft, such as that described in plate 1 being provided on the other, or exposed, face with a series of parallelly extending directional vanes 4.

The mounting bracket 2 is shaped in outline as shown in FIGURE 5, and is provided at its four end corners with lugs whereby it can be bolted to a discharge sec- 7 tion 6 of the apparatus in a position adjacent to the point the complete specification of my New Zealand Patent No.

123,228, wherein provision is made for propelling the craft astern by means of a forwardly directed propulsive jet of water.

The present invention has for its object the provision of a simple and easily mounted form of directional control means for apparatus of the above kind whereby the direction of the said forwardly directed propulsive jet may be altered so that the craft can be steered while it is being propelled astern by the said jet.

The control means provided by the invention consists essentially of. aplate adapted to be turnably mounted on hydraulic jet propulsion apparatus of the kind mentioned adjacent to the point of discharge of the said forwardly directed jet and provided on one face with a plurality of parallelly extending vanes which, when the plate is so mounted, lie in the path of the jet and serve to direct the jet in a desired direction, the plate being adapted for connection to steering means whereby the plate can be turned and the angle of the vanes in relation to the jet altered.

The plate may be adapted for mounting either directly on the apparatus, for example on a boss formed at an appropriate point thereon, or it may be turnably mounted on a mounting bracket which is provided with lugs or is otherwise adapted for fixed attachment to the apparatus. The mounting of the plate is conveniently effected in either case by means of a single pivot bolt, located approximately centrally of the plate, whereby the plate is secured to the boss or to the mounting plate or bracket, as the case may be.

Control means constituting one embodiment of the invention, and designed for use with the apparatus de* scribed in the complete specification of my aforementioned New Zealand patent, will now be described in more detail by way of example of how the invention can be carried into effect, and with reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation of a portion of the said apparatus, showing the control means mounted thereon; V

FIGURE 2 is a plan view from below of the portion of the said apparatus shown in FIGURE 1, showing the control means mounted thereon;

FIGURE 3 is a plan view from below of one member of the control means;

FIGURE 4 is a sectional elevation on the line a-a in FIGURE 3;

FIGURE 5 is a plan view from below of another member of the control means, and

FIGURE 6 is a side elevation of the member shown in FIGURE 5.

In the embodiment shown in the drawings, the control means consists of a plate 1 (shown particularly in FIG- URES 3 and 4) having the general shape of a segment which is greater than a semi-circle, and a mounting bracket 2 (shown particularly in FIGURES 5 and 6) to which the plate 1 is turnably attached by means of a pivot bolt 3 passing through a more or less central hole 3a in the plate 1, one face of the plate lying against a corresponding face of the mounting bracket 2, and the of discharge of the forwardly directed jet (indicated by arrows in FIGURES l and 2) when the craft is being propelled in the reverse direction, the vanes 4 then lying in the path of the jet. By turning the plate 1 around its pivot bolt 3, the angle of the vanes 4 in relation to the jet is altered, so as to deflect the jet to one side or the other and effect a corresponding alteration in the direction of rearward propulsion of the craft.

The vanes 4 are arranged at right angles to the chordal edge (In) of the plate 1 and extend across the plate 1 from that edge to the opposite arcuate edge (1b) of the plate, the plate 1 being so mounted that its latter edge is closest to the point of discharge of the jet. The vanes 4 are tapered from their ends at the arcuate edge 1b (hereinafter termed their leading ends), to their ends at the chordal edge 10: (hereinafter termed their trailing ends), so that the vanes 4 are of greatest depth at their leading ends, and decrease in depth progressively towards their trailing ends so as to substantially merge with the chordal edge In at their trailing ends. As it is the lead ing ends of the vanes 4 which are presented to the jet when the craft is being propelled in the reverse direction, the vanes 4 are tapered or streamlined so as to present substantially a knife edge at their leading ends.

The plate 1 is provided on one side with a laterally projecting portion forming a lug 7 which is adapted for connection by means of a suitable connecting rod 8 to steering mechanism 9 of the propulsion apparatus, in such a manner that the plate 1 of the control means can, by normal operation of the steering mechanism 9, be turned around its pivotal bolt 3 so as to alter the angle of the vanes 4 in relation to the forwardly directed jet, in the manner already described.

As is shown in FIGURES 1 and 2, the mounting bracket 2 is bolted to the underside of the discharge section 6 of the apparatus in a forwardly and downwardly inclined position in relation to the craft, so that the armate edge 1b of the plate 1 is on a higher level than its chordal edge In. The longitudinal tapering of the vanes 4 thus minimises the risk of damage to the vanes, particularly at their trailing end portions, which are most likely to come in contact with the bed of a stream or river on which the craft is travelling. Tofurther minimize this risk, particularly when the craft is travelling in a forward direction, the mounting bracket 2 is bolted to the discharge section 6 of the apparatus in a position in which the control means are on a higher level than that portion of the lower edge of the transom (1d) of the craft which lies directly forward of the control means, so that the control means are substantially shielded by the transom 10 during forward travel of the craft.

The vanes 4 are preferably four in number, as shown in the drawings, although a smaller or greater number may be used if desired,

The control means provided by the invention, when fitted to propulsion apparatus of the kind mentioned, renders possible the steering of the craft while the craft is being propelled .astern, and the location of the control means ensures that no part of the apparatus, including the control means, extends below the plane or planes of the undersurface of the hull of the craft. When the craft is travelling forwardly and planing at speed the control means, owing to their location in relation to the undersurface of the hull, are above the surface of the water passing beneath the lower edge of the transom 10 just forwardly of the control means, and thus do not aifect the direction of forward travel of the craft.

It will be apparent from the foregoing description that the directional control means provided by the invention are of a simple nature and can be manufactured without difficulty. At the same time the said control means provide an effective means of steering a craft fitted with the said propulsion apparatus While the craft is being propelled astern by means of a forwardly directed jet of water.

I claim:

1. For hydraulic jet propulsion apparatus for waterborne craft of the type including means for propelling the craft astern by means of a forwardly directed water jet, plate means constituting a directional control, means turnably mounting the plate means on the apparatus adjacent to the point of discharge of the forwardly directed jet, a plurality of vanes arranged in parallelism on and depending from the lower face of the plate means with such vanes lying in the path of the jet and serving to direct the jet in the desired direction, steering means aft of the plate means, and means connecting the plate means to the steering means whereby movement of the steering means effects turning of the plate means thereby changing the angle of the vanes in relation to the forwardly directed jet.

2. Control means according to claim 1, and including also a mounting bracket for the plate means adapted for fixed attachment to the apparatus.

3. Control means according to claim 1 and wherein the mounting means includes a single pivot bolt located approximately centrally of the plate means.

4. For hydraulic jet propulsion apparatus for waterborne craft of the type including means for propelling the craft astern by means of a forwardly directed water jet, plate means constituting a directional control, means turnably mounting the plate means on the apparatus adjacent to the point of discharge of the forwardly directed jet, a purality of vanes arranged in parallelism on the lower face of the plate means with such vanes lying in jet, a plurality of vanes arranged in parallelism on the desired direction, steering means aft of the plate means, and means connecting the plate means to the steering means whereby movement of the steering means effects turning of the plate means thereby changing the angle of the vanes in relation to the forwardly directed jet, the plate means having the general shape of a segment which is greater than a semi-circle, the plate means being mounted with its arcuate edge adjacent to the point of discharge of said jet and with its chordal edge remote from the point, and the vanes extending across the plate at right angles to its said chordal edge, and being tapered from their ends at the arcuate edge to their ends at the chordal edge, so that the vanes are of greatest depth at their former ends and decrease in depth progressively towards their latter ends so as to substantially merge with the chordal edge at their said latter ends, the vanes presenting substantially a knife edge at their said former ends.

5. Control means according to claim 1 including a laterally projecting portion forming a lug on the plate means which is adopted for connection to the connecting means.

6. Control means according to claim 1 including a mounting bracket for the plate means adapted for fixed attachment to the apparatus, said bracket being provided with lugs arranged at four end corners thereof and adapted to be bolted to the apparatus in a position adjacent to the point of discharge of the forwardly directed jet.

7. Control means as claimed in claim 1 including a transom for the craft, the plate means being mounted on the propulsion apparatus in a position in which such means are on a higher level than that portion of the lower edge of the transom which lies directly forward of the plate means, so that the plate means are substantially shieflded by the transom during forward travel of the era .t.

References Cited in the file of this patent UNITED STATES PATENTS 2,024,274 Campini Dec. 17, 1935 2,310,361 Ford Feb. 9, 1943 3,007,305 Hamilton Nov. 7, 1961 FOREIGN PATENTS 97,453 Austria July 10, 1924 118,815 New Zealand May 19, 1958 

1. FOR HYDRAULIC JET PROPULSION APPARATUS FOR WATERBORNE CRAFT OF THE TYPE INCLUDING MEANS FOR PROPELLING THE CRAFT ASTERN BY MEANS OF A FORWARDLY WATER JET, PLATE MEANS CONSTITUTING A DIRECTIONAL CONTROL, MEANS TURNABLY MOUNTING THE PLATE MEANS ON THE APPARATUS ADJACENT TO THE POINT OF DISCHARGE OF THE FORWARDLY DIRECTED JET, A PLURALITY OF VANES ARRANGED IN PARALLELISM ON AND DEPENDING FROM THE LOWER FACE OF THE PLATE MEANS WITH SUCH VANES LYING IN THE PATH OF THE JET AND SERVING TO DIRECT THE PLATE MEANS, AND MEANS CONNECTING THE PLATE MEANS OF THE PLATE MEANS, AND MEANS CONNECTING THE PLATE MEANS TO THE STEERING MEANS WHEREBY MOVEMENT OF THE STEERING MEANS EFFECTS TURNING OF THE PLATE MEANS THEREBY CHANGING THE ANGLE OF THE VANES IN RELATION TO THE FORWARDLY DIRECTED JET. 